SAN DIEGO, March 6, 2012 - Aragon Pharmaceuticals today announced that the company has secured $42 million in an oversubscribed Series C financing to advance Aragon's pipeline of therapies targeting hormone-driven cancers, including ARN-509, the company's lead compound for the treatment of castration-resistant prostate cancer (CRPC).

The company also announced data from the Phase I portion of an open-label, dose-escalating, Phase I/II clinical trial showing that ARN-509 was safe and well tolerated in patients with progressive metastatic CRPC and that ARN-509 demonstrated promising preliminary antitumor activity. Using prostate-specific antigen (PSA) analysis, investigators observed durable declines in levels of PSA in patients treated at all dose levels of ARN-509. The data were presented last month at the 2012 American Society for Clinical Oncology Genitourinary Cancers Symposium. Furthermore, enrollment in the Phase II portion of the study has been completed with clinical data anticipated later this year. The financing is led by a new investor, the Topspin Fund, an investment group of James Simons, Leo A. Guthart and Steve Winick, and includes the participation of existing investors Aisling Capital, OrbiMed Advisors and The Column Group. The financing brings the total amount of capital raised to $72 million since the company's founding in 2009.

"This $42 million round of financing puts Aragon on strong footing to execute on its promising pipeline in prostate cancer and breast cancer," said Richard A. Heyman, Ph.D., president and CEO of Aragon. "The addition of an investor like Topspin with a like-minded vision and considerable financial resources strategically provides Aragon with access to significant capital in the future. We are also tremendously excited about the progress we've made with our pipeline. The Phase II trial for ARN-509 initiated in November of 2011 is already fully enrolled well ahead of schedule. In addition, over the next year we will be aggressively advancing our second program into the clinic, which is targeting breast cancer via a novel mechanism for estrogen receptor degradation."

James Simons, Ph.D., co-founder of Topspin and the founder and former CEO of Renaissance Technologies, one of the world's most successful hedge funds, said, "The combination of Aragon's high quality management team, strong investor base and its novel insights into two of the most validated targets in oncology make the company an attractive investment."

In conjunction with the financing, Leo A. Guthart, CEO of Topspin Partners, will join Aragon's board of directors. Also joining Aragon's board as an independent director is Carol G. Gallagher, Pharm.D., the immediate past president and CEO of Calistoga Pharmaceuticals. While at Calistoga, Dr. Gallagher led a team of seasoned executives who advanced lead molecule CAL-101 into full development and secured a successful exit with the company's $600M acquisition by Gilead Sciences in April 2011.

Peter Svennilson, Aragon's chairman of the board, said, "Attracting high quality people like Carol Gallagher is a testament to Aragon's exciting trajectory. Carol's track record of success and depth of experience in oncology drug development and commercialization are of significant value as Aragon builds and progresses its pipeline. Aragon has made significant progress with great capital efficiency since its founding less than three years ago, and these recent milestones confirm that Aragon is well-positioned to move the next wave of novel compounds into the clinic."

About Aragon Pharmaceuticals

Aragon Pharmaceuticals is a privately held small-molecule drug discovery company founded in 2009 by Drs. Charles Sawyers, Michael Jung and Rich Heyman based upon the pioneering work of Dr. Sawyers identifying key molecular events that explain why the majority of prostate cancers become resistant to anti-hormonal therapies. This work has broad implications not only for prostate cancer but also for other hormone-dependent cancers such as breast and ovarian cancer and represents an opportunity to identify breakthrough medicines for the treatment of hormonally driven cancers. The company's lead compound, ARN-509, is being developed to treat patients with castration-resistant prostate cancer (CRPC). ARN-509 is an androgen receptor antagonist that inhibits nuclear translocation and DNA binding of the receptor, thereby modulating expression of genes that drive prostate cancer growth. In addition, Aragon has built a research and development team with expertise in oncology, nuclear receptor biology, medicinal chemistry and drug discovery to identify and develop selective degraders of nuclear hormone receptors, such as selective estrogen receptor degraders (SERDs) for hormone-sensitive and hormone-resistant estrogen receptor positive breast cancer. Its selective degrader research platform generates small-molecule drugs that not only bind to and block the hormone receptors that drive tumor growth, but also induce a conformational change in these proteins that results in their degradation.